The present invention relates generally to firestop devices and, more particularly, to a cast-in-place firestop device for passing cables, pipes, and the like through a concrete partition, such as a floor.
During the construction of buildings, it is necessary to provide openings or passages through the building floors, walls, and ceilings to permit the running of wires, cables, pipes, and the like. Such openings, however, which are often referred to as through-penetrations, provide one mechanism by which fire and smoke may spread from one compartment of the building to another.
Through-penetrations in poured concrete partitions may be formed by various techniques including knocking holes in the partition after it has been formed, or using a device which is arranged on a concrete form before the concrete is poured. Such devices may include an intumescent firestop material which expands and closes the opening in the partition in the event of a fire, thereby preventing the spread of fire and smoke from one compartment of the building to another. Such devices are often referred to as cast-in-place pass through firestop devices.
Cast-in-place firestop devices for providing a through-penetration in a partition that use intumescent material to close the passageway and prevent the spread of fire and smoke in the event of a fire are known in the patented art. The Harbeke U.S. Pat. No. 4,669,759, for example, discloses a firestop stack coupling including intumescent material which expands to close off a pipe passing through the coupling in the event of a fire. The Harbeke U.S. Pat. No. 4,888,925 discloses a fire retardant fluid coupling assembly having a metallic band wrapped about an intumescent collar.
The Roth U.S. Pat. No. 5,347,767 discloses a smoke and fire protection device for providing a heat sealable raceway for running wires and cables through a concrete wall, ceiling, or floor. The device includes a thermally expansive material which, in the event of a fire, expands causing the raceway to collapse, thus preventing fire and/or smoke from passing through the wall, ceiling, or floor. The raceway slidably fits within a tubular housing allowing the raceway to extend through the sleeve to either side of the device, thereby allowing an installer to couple additional sections of the raceway at a convenient location remote from the device. The sleeve has a length sized to accommodate the thickness of the particular mounting location. Since the sleeve is sized to accommodate a particular partition thickness, the user must pre-select the appropriate size sleeve for a particular job, thereby requiring installers to keep a large number of different size devices on hand.
The Rejecki U.S. Pat. No. 5,390,465 discloses a pass through firestop device for installation in a building wall or floor to provide a pass through opening for pipes, tubing, and the like. The device includes an axially open first end and a tubular body having a second end closed by a transverse wall. A ring of intumescent material fills the axially open first end. The device is installed during the formation of the building partitions by attaching the device to form elements and then pouring the floor or wall structure. After the floor is poured, the upper end section of the tubular body is removed by cutting it flush with the upper surface of the floor.
The Mxc3xcnzenberger et al. U.S. Pat. No. 6,161,873 discloses a masonry lead-in fixture having a housing including an axially extending through bore, a radially protruding attachment flange provided at least at one end of the housing, an intumescent material which, in case of fire, closes the bore, and a disc-shaped partition located in the housing which extends over the inner diameter of the bore which is broken when pipe, cable, or the like is pushed through the fixture. The fixture includes a lengthening pipe formed of a plastic material that is cut-off to a desired length.
Thus, there remains a need in the industry for a cast-in-place pass through device for providing a heat sealable passageway through partitions such as floors, walls, or ceilings in a structure such as a building for running cables, wires, pipes, and the like, that can be quickly and easily installed in partitions having varying thicknesses. In addition, there remains a need for such a device that allows for early, fast, uniform, and complete expansion of the intumescent material in case of a fire.
It would therefore be desirable to provide a cast-in-place pass through firestop device for providing a heat sealable passageway in a partition that can be used in partitions of various thicknesses, and which further allows the intumescent material to quickly and completely expand when exposed to temperatures typically encountered during a fire.
The present invention provides a firestop device for providing a passage through a partition in a structure comprising a housing and firestop material arranged within the housing, wherein the housing includes at least one frangible connection transecting the housing. The term firestop material refers generally to intumescent, endothermic, and ablative materials useful in resisting the spread of fire and smoke from one compartment of a structure to another.
The frangible connection can be formed in the housing by providing a line of weakness in the housing by, for example, scoring, notching, or creasing the housing, or by molding or machining the housing to have a thin region in the wall, thereby allowing a user to easily tear the housing along the line of weakness. The frangible connection defines a removable band that can be readily removed by a user, typically with the aid of a hand tool such as pliers, to shorten the length of the housing to accommodate the thickness of the partition into which the device is installed. The removable band preferably includes a pull tab that provides grasping means for a user to remove the band from the housing along the frangible connection, thereby facilitating manual removal of the band.
In a specific embodiment, the housing includes a base portion and a riser portion, the base portion including a recess adapted to receive the firestop material, and the riser portion including the frangible connection. The base portion includes a sidewall portion and a shoulder portion that combine to define the recess. The sidewall portion extends from a first open end toward the riser portion, and the shoulder portion extends inwardly from the sidewall portion to the riser portion.
In one aspect of the invention, the sidewall and the shoulder portions include inner surfaces having ribs. The sidewall ribs serve to maintain the firestop material in the recess in spaced relation to the sidewall, thereby creating a gap between the firestop material and the sidewall that allows heated air from a fire to more completely surround the firestop material, thereby providing earlier, more uniform, and more complete expansion of the firestop material.
In one embodiment, a gasket is provided between the firestop material and the shoulder portion to provide a seal that prevents water and smoke from passing through the opening prior to expansion of the firestop material. The shoulder portion rib helps retain the gasket in place.
In another aspect of the invention, the housing has first and second opposed open ends and a hollow chamber having a longitudinal axis extending from the first open end to the second open end. The first open end is provided in the base portion and the second open end is provided in the riser portion. The firestop material is provided along the sidewall portion inner surface from the first open end to the shoulder portion.
In a more specific aspect of the invention, the housing has a two-tiered cylindrical shape with the base portion having a larger diameter than the riser portion. The base portion may also include a radially outwardly extending flange extending outwardly from the periphery of the base portion adjacent the first open end for fixing the device to a form. In one embodiment, the flange extends outwardly 360 degrees around the base portion, and in another embodiment, two separate flanges extending radially outwardly from opposite sides of the base portion are provided to allow for closer stacking of adjacent devices.
The riser portion preferably includes a plurality of equally sized transverse bands each including a manually engageable pull tab to facilitate manual removal of the associated bands with or without the aid of a manually operated hand tool. By removing successive bands, a user can adjust the length of the device (i.e. shorten) in accordance with the thickness of the partition into which the device is installed. It will be recognized that providing more bands will increase the range of partition thicknesses that can be accommodated by the device, and increasing the number of bands per unit length will increase the ability of the device to more closely match the thickness of the partition. In addition, the pull tabs on each band may be provided with indicia indicating the length of the device at the band and corresponding to the thickness of the partition. Each band may also include one or more radially outwardly extending circumferential ribs that provide the bands and, consequently, the riser with added hoop strength, and also provide a projection for making snap connections.
In another aspect of the invention, the device includes a cap that is attached to the riser portion of the device to cover the second open end. In one embodiment, the cap includes cantilevers that snap onto the circumferential ribs, thereby securely attaching the cap to the riser portion. The firestop device may also include an extension member adapted to connect with the riser portion to increase the length of the device and allow the device to be used with partitions having thicknesses greater than the standard length of the device. The outer diameter of the extension is preferably sized so that standard size plastic pipe can fit over and connect with the extension to provide additional extension for the device.
In another aspect of the invention, the device includes a retaining ring arranged within the base portion first open end adjacent the firestop material that serves to retain the firestop material in the base portion. The retaining ring may be coded with color or other indicia to indicate the quantity of firestop material provided in the device which, in turn, corresponds with the application of the device. An adapter may also be provided that connects with the base portion to allow the device to be coupled to a contoured surface such as a fluted or corrugated deck.
In a specific embodiment, the present invention provides a firestop device for providing a passage through a partition in a structure comprising a housing having first and second opposed open ends and a hollow chamber having a longitudinal axis extending from the first open end to the second open end, the housing including a cylindrical base portion having a diameter and a cylindrical riser portion having a diameter smaller than the base diameter, the base portion including an annular sidewall portion extending from the first open end toward the riser portion and a shoulder portion extending radially inwardly from the sidewall portion to the riser portion, the sidewall portion and the shoulder portion defining an annular recess for receiving firestop material, the sidewall and the shoulder portions including inner surfaces having inwardly extending ribs, the riser portion including a plurality of longitudinally arranged frangibly connected circumferential bands having equal axial lengths, each band including a radially outwardly extending pull tab that can be used to remove an associated band from the riser portion along a frangible connection, thereby to reduce the height of the device in accordance with the thickness of the partition into which the device is installed.
In another aspect of the invention, which is particularly useful for when a metal pipe is passed through the device, a flame retardant char forming material is provided within the housing adjacent the firestop material, preferably adjacent the inner surface of the firestop material. In a specific embodiment, the flame retardant char forming material is an annular band arranged concentrically within the firestop material. The flame retardant char forming material serves to strengthen the expanded intumescent material such that the resulting mass forms a fire barrier that can pass the hose stream portion of ASTM E 814 Fire Test Standard.